Rotary engines are an alternative to conventional piston driven engines. One of the challenges in the design of rotary engines is the problem of isolating the various stages of the combustion cycle from one another while striving to maximize the efficiency of the engine.
One solution to this challenge uses abutments which separate the housing in which the rotor rotates into various isolated chambers, each chamber being dedicated to a particular phase of the combustion cycle. The abutments generally move linearly in timed relation to the rotary motion of the rotor.
Various abutment type rotary engines have been patented. The following patents are believed to be representative of the prior art: U.S. Pat. Nos. 6,962, 1,061,107, 1,721,855, 1,846,298, 2,045,081, 3,040,530, 3,323,500, German Patent 356,724, French Patent 1,131,238, and British Patent 4,627. Abutment type rotary engines known in the prior art generally suffer from a common problem: the inability to move the abutments smoothly and efficiently in timed relation to the rotor, while sealing the chambers formed by the abutments and rotor housing from each other. In most prior art abutment type rotary engines, in order to seal the chambers formed by the abutments and rotor housing, springs are employed to bias the abutments against the surface of the rotor. The spring force causes excessive wear on both the rotor and abutments, which degrades the seal and reduces the overall efficiency of the engine.
U.S. Pat. No. 1,846,298 to Alcznauer describes an abutment type of rotary engine which uses a gear mechanism coupled to the rotor of the engine which is involved in moving the abutments. However, the abutments are retracted relative to the rotor by cams mounted on a shaft, and the abutments are held in engagement with the rotor by springs and rocker arms, again causing wear on the rotor and abutments.
U.S. Pat. No. 5,579,733 to the present applicant/assignee, the disclosure of which is incorporated herein by reference, discloses a mechanically efficient, rotary engine with abutments. The abutments move in timed relation to the rotor using a gear train without cams, and no biasing devices force the abutments against the surface of the rotor. In addition, the engine requires no valves. The engine is suitable for use not only as an internal combustion engine, but also as a power source for compressors and pumps for liquids and gases.